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-rw-r--r--include/linux/signal.h125
-rw-r--r--kernel/signal.c119
2 files changed, 125 insertions, 119 deletions
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 14749056dd63..3fa0fab4a04b 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -243,6 +243,131 @@ extern int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
243 243
244extern struct kmem_cache *sighand_cachep; 244extern struct kmem_cache *sighand_cachep;
245 245
246/*
247 * In POSIX a signal is sent either to a specific thread (Linux task)
248 * or to the process as a whole (Linux thread group). How the signal
249 * is sent determines whether it's to one thread or the whole group,
250 * which determines which signal mask(s) are involved in blocking it
251 * from being delivered until later. When the signal is delivered,
252 * either it's caught or ignored by a user handler or it has a default
253 * effect that applies to the whole thread group (POSIX process).
254 *
255 * The possible effects an unblocked signal set to SIG_DFL can have are:
256 * ignore - Nothing Happens
257 * terminate - kill the process, i.e. all threads in the group,
258 * similar to exit_group. The group leader (only) reports
259 * WIFSIGNALED status to its parent.
260 * coredump - write a core dump file describing all threads using
261 * the same mm and then kill all those threads
262 * stop - stop all the threads in the group, i.e. TASK_STOPPED state
263 *
264 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
265 * Other signals when not blocked and set to SIG_DFL behaves as follows.
266 * The job control signals also have other special effects.
267 *
268 * +--------------------+------------------+
269 * | POSIX signal | default action |
270 * +--------------------+------------------+
271 * | SIGHUP | terminate |
272 * | SIGINT | terminate |
273 * | SIGQUIT | coredump |
274 * | SIGILL | coredump |
275 * | SIGTRAP | coredump |
276 * | SIGABRT/SIGIOT | coredump |
277 * | SIGBUS | coredump |
278 * | SIGFPE | coredump |
279 * | SIGKILL | terminate(+) |
280 * | SIGUSR1 | terminate |
281 * | SIGSEGV | coredump |
282 * | SIGUSR2 | terminate |
283 * | SIGPIPE | terminate |
284 * | SIGALRM | terminate |
285 * | SIGTERM | terminate |
286 * | SIGCHLD | ignore |
287 * | SIGCONT | ignore(*) |
288 * | SIGSTOP | stop(*)(+) |
289 * | SIGTSTP | stop(*) |
290 * | SIGTTIN | stop(*) |
291 * | SIGTTOU | stop(*) |
292 * | SIGURG | ignore |
293 * | SIGXCPU | coredump |
294 * | SIGXFSZ | coredump |
295 * | SIGVTALRM | terminate |
296 * | SIGPROF | terminate |
297 * | SIGPOLL/SIGIO | terminate |
298 * | SIGSYS/SIGUNUSED | coredump |
299 * | SIGSTKFLT | terminate |
300 * | SIGWINCH | ignore |
301 * | SIGPWR | terminate |
302 * | SIGRTMIN-SIGRTMAX | terminate |
303 * +--------------------+------------------+
304 * | non-POSIX signal | default action |
305 * +--------------------+------------------+
306 * | SIGEMT | coredump |
307 * +--------------------+------------------+
308 *
309 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
310 * (*) Special job control effects:
311 * When SIGCONT is sent, it resumes the process (all threads in the group)
312 * from TASK_STOPPED state and also clears any pending/queued stop signals
313 * (any of those marked with "stop(*)"). This happens regardless of blocking,
314 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
315 * any pending/queued SIGCONT signals; this happens regardless of blocking,
316 * catching, or ignored the stop signal, though (except for SIGSTOP) the
317 * default action of stopping the process may happen later or never.
318 */
319
320#ifdef SIGEMT
321#define SIGEMT_MASK rt_sigmask(SIGEMT)
322#else
323#define SIGEMT_MASK 0
324#endif
325
326#if SIGRTMIN > BITS_PER_LONG
327#define rt_sigmask(sig) (1ULL << ((sig)-1))
328#else
329#define rt_sigmask(sig) sigmask(sig)
330#endif
331#define siginmask(sig, mask) (rt_sigmask(sig) & (mask))
332
333#define SIG_KERNEL_ONLY_MASK (\
334 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
335
336#define SIG_KERNEL_STOP_MASK (\
337 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \
338 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) )
339
340#define SIG_KERNEL_COREDUMP_MASK (\
341 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \
342 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \
343 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \
344 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \
345 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \
346 SIGEMT_MASK )
347
348#define SIG_KERNEL_IGNORE_MASK (\
349 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
350 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
351
352#define sig_kernel_only(sig) \
353 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_ONLY_MASK))
354#define sig_kernel_coredump(sig) \
355 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_COREDUMP_MASK))
356#define sig_kernel_ignore(sig) \
357 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_IGNORE_MASK))
358#define sig_kernel_stop(sig) \
359 (((sig) < SIGRTMIN) && siginmask(sig, SIG_KERNEL_STOP_MASK))
360
361#define sig_needs_tasklist(sig) ((sig) == SIGCONT)
362
363#define sig_user_defined(t, signr) \
364 (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \
365 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
366
367#define sig_fatal(t, signr) \
368 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
369 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
370
246#endif /* __KERNEL__ */ 371#endif /* __KERNEL__ */
247 372
248#endif /* _LINUX_SIGNAL_H */ 373#endif /* _LINUX_SIGNAL_H */
diff --git a/kernel/signal.c b/kernel/signal.c
index 1368e67c8482..4c8f49eadf7d 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -38,125 +38,6 @@
38 38
39static struct kmem_cache *sigqueue_cachep; 39static struct kmem_cache *sigqueue_cachep;
40 40
41/*
42 * In POSIX a signal is sent either to a specific thread (Linux task)
43 * or to the process as a whole (Linux thread group). How the signal
44 * is sent determines whether it's to one thread or the whole group,
45 * which determines which signal mask(s) are involved in blocking it
46 * from being delivered until later. When the signal is delivered,
47 * either it's caught or ignored by a user handler or it has a default
48 * effect that applies to the whole thread group (POSIX process).
49 *
50 * The possible effects an unblocked signal set to SIG_DFL can have are:
51 * ignore - Nothing Happens
52 * terminate - kill the process, i.e. all threads in the group,
53 * similar to exit_group. The group leader (only) reports
54 * WIFSIGNALED status to its parent.
55 * coredump - write a core dump file describing all threads using
56 * the same mm and then kill all those threads
57 * stop - stop all the threads in the group, i.e. TASK_STOPPED state
58 *
59 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
60 * Other signals when not blocked and set to SIG_DFL behaves as follows.
61 * The job control signals also have other special effects.
62 *
63 * +--------------------+------------------+
64 * | POSIX signal | default action |
65 * +--------------------+------------------+
66 * | SIGHUP | terminate |
67 * | SIGINT | terminate |
68 * | SIGQUIT | coredump |
69 * | SIGILL | coredump |
70 * | SIGTRAP | coredump |
71 * | SIGABRT/SIGIOT | coredump |
72 * | SIGBUS | coredump |
73 * | SIGFPE | coredump |
74 * | SIGKILL | terminate(+) |
75 * | SIGUSR1 | terminate |
76 * | SIGSEGV | coredump |
77 * | SIGUSR2 | terminate |
78 * | SIGPIPE | terminate |
79 * | SIGALRM | terminate |
80 * | SIGTERM | terminate |
81 * | SIGCHLD | ignore |
82 * | SIGCONT | ignore(*) |
83 * | SIGSTOP | stop(*)(+) |
84 * | SIGTSTP | stop(*) |
85 * | SIGTTIN | stop(*) |
86 * | SIGTTOU | stop(*) |
87 * | SIGURG | ignore |
88 * | SIGXCPU | coredump |
89 * | SIGXFSZ | coredump |
90 * | SIGVTALRM | terminate |
91 * | SIGPROF | terminate |
92 * | SIGPOLL/SIGIO | terminate |
93 * | SIGSYS/SIGUNUSED | coredump |
94 * | SIGSTKFLT | terminate |
95 * | SIGWINCH | ignore |
96 * | SIGPWR | terminate |
97 * | SIGRTMIN-SIGRTMAX | terminate |
98 * +--------------------+------------------+
99 * | non-POSIX signal | default action |
100 * +--------------------+------------------+
101 * | SIGEMT | coredump |
102 * +--------------------+------------------+
103 *
104 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
105 * (*) Special job control effects:
106 * When SIGCONT is sent, it resumes the process (all threads in the group)
107 * from TASK_STOPPED state and also clears any pending/queued stop signals
108 * (any of those marked with "stop(*)"). This happens regardless of blocking,
109 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
110 * any pending/queued SIGCONT signals; this happens regardless of blocking,
111 * catching, or ignored the stop signal, though (except for SIGSTOP) the
112 * default action of stopping the process may happen later or never.
113 */
114
115#ifdef SIGEMT
116#define M_SIGEMT M(SIGEMT)
117#else
118#define M_SIGEMT 0
119#endif
120
121#if SIGRTMIN > BITS_PER_LONG
122#define M(sig) (1ULL << ((sig)-1))
123#else
124#define M(sig) (1UL << ((sig)-1))
125#endif
126#define T(sig, mask) (M(sig) & (mask))
127
128#define SIG_KERNEL_ONLY_MASK (\
129 M(SIGKILL) | M(SIGSTOP) )
130
131#define SIG_KERNEL_STOP_MASK (\
132 M(SIGSTOP) | M(SIGTSTP) | M(SIGTTIN) | M(SIGTTOU) )
133
134#define SIG_KERNEL_COREDUMP_MASK (\
135 M(SIGQUIT) | M(SIGILL) | M(SIGTRAP) | M(SIGABRT) | \
136 M(SIGFPE) | M(SIGSEGV) | M(SIGBUS) | M(SIGSYS) | \
137 M(SIGXCPU) | M(SIGXFSZ) | M_SIGEMT )
138
139#define SIG_KERNEL_IGNORE_MASK (\
140 M(SIGCONT) | M(SIGCHLD) | M(SIGWINCH) | M(SIGURG) )
141
142#define sig_kernel_only(sig) \
143 (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_ONLY_MASK))
144#define sig_kernel_coredump(sig) \
145 (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_COREDUMP_MASK))
146#define sig_kernel_ignore(sig) \
147 (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_IGNORE_MASK))
148#define sig_kernel_stop(sig) \
149 (((sig) < SIGRTMIN) && T(sig, SIG_KERNEL_STOP_MASK))
150
151#define sig_needs_tasklist(sig) ((sig) == SIGCONT)
152
153#define sig_user_defined(t, signr) \
154 (((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_DFL) && \
155 ((t)->sighand->action[(signr)-1].sa.sa_handler != SIG_IGN))
156
157#define sig_fatal(t, signr) \
158 (!T(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
159 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
160 41
161static int sig_ignored(struct task_struct *t, int sig) 42static int sig_ignored(struct task_struct *t, int sig)
162{ 43{
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-12 08:03:09 -0500